Various cleaning techniques have been used in producing semiconductor devices (for instance, see Japanese Patent Laid-open Publication No. 2001-53050). The available cleaning techniques include, for instance, treatment with dilute aqueous hydrofluoric acid solution (DHF), aqueous ammonia and hydrogen peroxide mixture solution (APM), or aqueous hydrochloric acid and hydrogen peroxide mixture solution (HPM). Note that DHF treatment, for instance, is not always intended for cleaning alone, but it may also be performed, for instance, for removing a silicon oxide film from a particular region.